1. Field of the Invention
The present invention relates to an improved means for lifting and rigging pipe flanges into position onto a pipe end. More specifically, the present invention pertains to a device for lifting medium to large blind and weld neck flanges into position for installation in a way that improves worker safety and control of the flange during installation or removal.
2. Description of the Prior Art
Many industries utilize piping systems to facilitate daily operations. For example, oil refineries, gas companies and sewage treatment facilities need to pump and store large volumes of gases and/or liquids. The transport and storage systems for these products are large and are designed for durability and safety, as any leaks could be extremely hazardous and costly. Typically, piping systems are connected together at various junctions and joints to prevent such leaks. Piping systems generally comprise an array of individual segments that connect together to form an entire network for transporting a substance therethrough. The present invention pertains specifically to pipe flange fittings and a tool to aid installation and removal thereof. Pipe flanges are utilized to secure a pipe closed or to weld a new section of equal diameter piping to a pipe end. These fittings are generally considerably heavy and cumbersome components that require specific techniques and safety precautions when installing or removing. Their size and weight necessitates the use of a mechanical lift device, such as a crane or mechanical hoist, in order to property rig the flange into place during installation, or to control the flange during removal.
Blind flanges are flat, disk-like covers that affix over the ends of open pipes. They are often difficult to lift and position because of their weight and their shape. A traditional procedure for lifting such a flange involves inserting a chain or lifting bolt through an eye of the flange and then using the chain or hoist to lift the flange. This method is highly hazardous to worker safety because any broken link in the chain could result in the flange becoming loose and falling to the ground. This method further does not provide the level of stability necessary for a safe installation, as a chain or single lifting point does not guarantee the device will not rotate while being positioned. The use of ad hoc tools or impromptu support means is both dangerous for personnel and to the equipment being utilized. The instability of such a support also introduces a pinching risk for workers operating near the suspended flange and the pipe end, whereby clothing and limbs may be compressed therebetween if the flange is not securely supported. Worker safety is paramount in such work environments and around construction sites, as accidents can lead to considerable injury to those involved if adequate precautions are not taken and appropriate tools are not utilized.
Weld neck flanges are similar to blind flanges; however these offer a long, tapered hub surrounding an open central region, wherein the hub distal end is used to weld a connecting pipe thereto utilizing a buttweld joint. This type of flange allows for connection of an equal diameter pipe to be welded to the hub using the buttweld joint, which creates a join that is well suited for high pressure applications and extreme temperature fluctuations. These types of flanges, as with all pipe flanges, employ a plurality of securement bolt eyes around their perimeter. The weld neck flange protruding hub, however, extends from its central region and limits the ability of workers to place a lifting tool beneath a pair of lifting bolts fitted through the eyes of the flange during installation or removal. This prohibits a worker's ability to support a lifting bolt from the hub-side of the flange, which limits the stability and safety of an operation in which the flange is supported from only from one side.
The present invention is disclosed for the purposes of supporting any a plurality of industrial fittings, including any type of flange having one or a plurality of eyes, regardless of the flange central hub geometry. The present invention employs a pair of pivotable members that are positioned on opposing sides of the flange and are utilized to support lifting pins placed through the flange eye locations. A pair of pins and the flange eyes are supported by the members in a static configuration, whereafter a mechanical lift hoists the assembly into position if the flange is being installed. During removal, the two securement bolts from the flange installation are removed and the remaining connections are loosened to separate the flange from the pipe end while still retaining connectivity. The separation allows a user to position the present invention members on opposing sides of the flange. The support pins are fitted through the two open eyes to support the flange as all remaining bolts are removed, allowing the flange to be stably supported and controlled once the flange is free of the pipe. The pivotable members do no overlap any major portion of the flange central region, other than the eye locations, allowing for its use in conjunction with blind, lap joint, slip-on, socket weld, threaded or weld neck flanges.
Several specialized devices exist in the market and in the prior art that facilitate the lifting of heavy industrial assembly components. These devices have familiar design elements for the purposes of supporting an article using a crane hoist, wherein the supported element is otherwise unwieldy or cumbersome to handle. However, these devices fail to disclose the novel features of the present invention, and are limited to a specific use outside of the scope of supporting pipe flanges and other industrial assemblies having lifting eyes. These prior art devices include those that have been patented or published in patent application publications. The devices deemed most relevant to the present disclose are provided below.
Specifically, U.S. Pat. No. 4,530,536 to Williams describes a set of lifting tongs for use in conjunction with a crane for lifting I-beams. The device is designed for use by a single individual. The tongs are opened and closed by the operation of a pneumatic piston at the upper end of the set of tongs. A set of jaws exists at the lower ends of the tongs having a groove cut into the interior face of each jaw. The grooves are specifically designed to catch the edges of the top flange of an I-beam. A crane operator lowers the lifting tongs device around the sides of the beam that is to be lifted. The crane operator then operates the closing mechanism of the tongs. As the tongs close, the jaws come together to secure against the upper flange of the beam. The jaws are designed so that as the jaws are closing, if the crane operator slowly lifts the device with the crane hoist, the jaws catch the edges of the top flange of the beam within the jaw grooves.
The Williams device is particularly designed for the purpose of lifting I-beams. While the Williams device serves an important function by lifting such beams, the device could not be used for lifting pipe flanges. The jaw and groove mechanism employed by the Williams device for catching the top edge flanges of an I-beam could not be used to grip the edges of a blind flange or support a pair of lifting bolts attached thereto, since the diameter of a blind flange is very likely to exceed the span of the top edge flanges of an I-beam and the tongs are not adapted to support the two bolts in a secure and stable manner.
U.S. Pat. No. 5,065,984 to Hake is another device that describes a clamp assembly device for lifting pins out of concrete forms. When concrete is poured, the outer edges of what is poured must be shaped into the desired form. A concrete form is typically a metal frame that is made from smaller segments of the form combined together to make the overall form of the concrete slab to be laid. The smaller portions of the frame fit together like puzzle pieces—connected to one another and held together via pins. The device attaches to a lifting mechanism, which can be a piece of industrial equipment that allows for an upward lifting element that facilitates lift needed when using the disclosed device. The lifting mechanism is important when using the Hake device properly as the pins must be removed from the concrete forms by pulling directly upward. Pulling the pins any direction other than vertically will damage the pin, the concrete form, or both. While suited for its particular requirement, the Hake device is limited to lifting concrete form pins. The present invention provides a lifting mechanism for use with a lifting mechanism, such as a crane or hoist, and is particularly suited for lifting pipe flanges into position for attachment onto a large pipe assembly or pipe end, or further for removal thereof.
U.S. Pat. No. 5,344,207 to Grimm describes an apparatus for lifting tires that is used in conjunction with a lifting device, such as a crane. The device comprises two members for gripping a tire and a means for connecting to a crane. The first member is stationary, while the second member is movable. The second member has two positions: a tire lifting position and a tire non-lifting position. To use the device, a tire is placed between the two members when the second member of the device is in the non-lifting position. Once the tire is in properly placed in the device, the second member is moved by a user to the tire lifting position and locks into place so that the tire is gripped by the two members of the device.
Similar to the Grimm device is U.S. Pat. No. 5,064,334 to Cooley, wherein an apparatus for lifting large tractor tires is disclosed. The size of tractor tires makes them difficult to maneuver without the assistance of a lifting device. The Cooley device aims to lift and move tractor tires easily. When a tractor tire is standing upright on the tread, the Cooley device attaches to the tire by an attachment means. The tire attachment means connects to a boom, which is raised and lowered by a hand jack. The boom connects to a base and the boom is also capable of being pivotally rotatable to facilitate moving of the tractor tire from one point to another. One embodiment of the tire attachment means is a square-shaped clamp. The arms of the clamp extend around the sides of the tractor tire with the ends of the clamp arms wrapping under the rim of the tire so that when the clamp is closed around the tire, the tire is caught in the clamp. The boom can then be lifted, lifting the attached tractor tire with it by operating the hand jack.
Both the Grimm and Cooley devices are specifically suited for lifting tires. Each device employs a clamping mechanism is designed to grip, lift and suspend a tire. The clamping mechanisms of the Grimm and Cooley devices do not support the tire from below its structure in any way. The clamps merely pinch under the tire carcass such that the clamps encircle the sidewall and enter through the wheel opening. While it is unlikely, if the clamping mechanism of either the Grimm or Cooley devices were to fail, the tire would release or drop from the grip of the device. Such an accident could harm an individual or damage property. The present invention differs in spirit and intent from the Grimm and Cooley device and is particularly suited for lifting large objects having lifting eye locations, such as pipe flanges and similar industrial equipment.
U.S. Pat. No. 5,842,729 to Bunn describes a device for lifting large sections of heavy pipe. The device comprises a pair of lifting tongs that attach to a crane hoist or other lifting means. The tongs have two ends and are connected to each other at a pivot point. The bottom end of each tong curves inward towards the center of the tongs such that as the tongs close, they wrap around the cylindrical shape of the pipe cross section being moved. The top end of each tong connects to the other by a highly durable cable. The cable is looped through a lifting means, such as a crane hoist or a forklift. As the crane hoist or forklift rises, it pulls upward on the cable connecting the two top ends of the tongs, causing the top ends of the tongs to move towards one another. The tongs are positioned in a scissor configuration, wherein the cable action on the tongs compresses the working ends of the tongs around a pipe section. As the top ends of the tongs move towards each other, the bottom ends also compress towards each other, wrapping around the section of cylindrical piping. These tongs are not suited for adequately lifting or supporting lift bolts of a flange. The scissor action provides lateral compression but inadequate support under the flange bolts, which is necessary for safely and securely lifting a blind flange. The present invention provides a means to support a pipe flange and lift bolts fitted through eyes of the flange such that a secure and safe lifting assembly is provided.
The present invention provides an industrial lifting tool having a pair of rotatable members that are rotatably connected and offset from one another via a common pin attachment. The members employ an aperture through which is adapted to be placed a lifting bolt inserted therethrough and into an eye along the periphery of an industrial flange assembly. The members attaches along opposing sides of the flange and provide a stable support means that resists dislodgement during lifting and pipe end fitting operations. Spacers along the common pin provide the offset between members, while the tool itself is separable into its base elements to accommodate long common pins and more or fewer spacers thereon. The spacers prevent the rotatable members from binding or creating pinch points along the pin. In light of the foregoing prior art the elements of the present disclosure, it is submitted that the present invention substantially divergent from existing lifting devices, and consequently it is clear that there is a need in the art for an improvement to existing flange lifting devices. In this regard, the instant invention substantially fulfills these needs by providing a universal lifting device.